1. Field of the Invention
The invention relates to a communication device and particularly relates to a wrist-worn communication device.
2. Description of Related Art
As the technology of mobile communication advances in the recent years, mobile communication devices are being developed to provide more and diverse functions. Because of the trend of the market and expectation of the consumers, wearable communication devices (e.g. smart watch, smart glasses, etc.) are drawing more and more attention. In particular, the design of a communication device for smart watches needs to have the characteristics of being compact in size and easy to wear. However, such a design may result in an excessively small ground plane and cause that the antenna element of the communication device cannot be operated in a low frequency band of mobile communication (e.g. the frequency band of 900 MHz). Therefore, how to enable an antenna element, applicable to a wrist-worn communication device, to perform multi-band operation to cover the low frequency band has become an important issue.